CN116036349A

CN116036349A - Flexible and thin daily absorbent core with red buttock prevention function and extremely rapid absorption capacity and application thereof

Info

Publication number: CN116036349A
Application number: CN202310032155.2A
Authority: CN
Inventors: 张谭妹; 周彧峰; 彭海燕; 潘嘉丽; 聂志强; 周峰; 邹超
Original assignee: Lule Health Technology Co Ltd
Current assignee: Lule Health Technology Co Ltd
Priority date: 2023-01-10
Filing date: 2023-01-10
Publication date: 2023-05-02
Anticipated expiration: 2043-01-10
Also published as: CN116036349B

Abstract

The invention relates to a flexible and thin daily absorbent core with red buttock prevention function and extremely rapid absorption capacity and application thereof. The invention adopts the water-absorbent resin with a specific structure in the absorbent core, and has the advantages of high absorption capacity, high liquid absorption rate and low rewet. Therefore, the absorbent core has excellent instant absorption capability, and the condition of urine leakage caused by the excessive activities of infants in daytime can not occur; the diaper has high liquid absorption rate, high liquid absorption rate and low rewet quantity, can reduce the time of direct contact between the buttocks of a baby and excrement, has strong air permeability, and can solve the problems of urine leakage and red buttocks of the diaper; meanwhile, the texture is light, thin and soft. Therefore, it is particularly suitable for use in daytime.

Description

Flexible and thin daily absorbent core with red buttock prevention function and extremely rapid absorption capacity and application thereof

Technical Field

The invention relates to the field of sanitary products, in particular to a flexible and thin daily absorbent core with red buttocks prevention function and extremely quick absorption capacity and application thereof.

Background

The paper diaper product has various types and different effects, but the structure of the paper diaper product mainly comprises four parts, namely a skin-friendly surface layer, a diversion layer, an absorption core body and a back layer, wherein the absorption core body is the most important component part in the paper diaper, and is required to quickly absorb urine, quickly diffuse the urine into the whole absorption core body by diversion and wicking action, and then quickly absorb and lock the urine by a water absorbing material, so that the urine is not reverse-penetrated. The absorbent core is the core of the whole diaper. The liquid absorption amount and the absorption speed of the core layer directly influence the quality and the service time of the paper diaper.

However, it was found in the investigation that the use of the baby diaper still had problems of "red buttocks", leakage of urine, and the like. The main reasons for the generation of the red buttocks are that the absorption rate of the absorption core body is not fast enough, the absorption multiplying power is not high enough and the rewet amount is too large, so that the surface layer of the paper diaper is not fresh any more, and skin can be wrinkled under the condition of too much moisture for a long time; in addition, after the diaper absorbs liquid, the super absorbent resin absorbs the liquid to generate gel, so that excessive liquid cannot be absorbed to form gel blocking, the diaper is poor in air permeability, and the phenomenon of red buttocks is aggravated. At present, the absorbent core body mostly uses super absorbent resin as a main absorbent material, and the super absorbent resin is mixed with fluff pulp or dust-free paper, non-woven fabrics, swelling paper and the like, and the performance of the super absorbent resin determines the absorbent core body.

Therefore, how to increase the liquid absorption rate, the liquid absorption rate and reduce the rewet amount of the water absorbent resin is a key for solving the red buttocks problem.

Disclosure of Invention

Aiming at the problems existing in the prior art, the invention provides an absorbent core with high-speed absorption capacity, which adopts water-absorbent resin with high-speed absorption capacity as a water-absorbent material, has high liquid passing rate and low rewet amount, and can keep sanitary products such as paper diapers and the like dry and cool in the use process, thereby reducing the occurrence of red buttocks.

The absorbent core of the present invention comprises, in order from top to bottom: a top layer, a middle layer and a bottom layer;

the intermediate layer comprises water-absorbent resin particles, wherein the water-absorbent resin is sodium polyacrylate copolymerized maleic anhydride grafted polyvinyl alcohol, and pentaerythritol diacrylate and epichlorohydrin are used as cross-linking agents.

In one embodiment, the top layer is liquid permeable. The top and bottom layers may be woven, nonwoven, dust free paper, or the like.

In one embodiment, the intermediate layer comprises water absorbent resin particles and a carrier for supporting the water absorbent resin particles, the carrier comprising at least one of fluff pulp, porous nonwoven material, porous woven material, tissue layer.

In one embodiment, the water absorbent resin particles are present in the absorbent core in an amount of greater than 40%, preferably greater than 50%, or greater than 60%, greater than 70%, most preferably greater than 80%.

In one embodiment, the water absorbent resin is prepared by the following method:

diluting a certain amount of acrylic acid with a proper amount of water, neutralizing the solution to a certain neutralization degree by using a sodium hydroxide solution at a temperature of 0-10 ℃, adding a certain amount of maleic anhydride grafted polyvinyl alcohol, and stirring to completely dissolve; continuously adding an initiator and a stabilizer under the protection of inert gas, then dropwise adding a solution of a cross-linking agent pentaerythritol diacrylate and epichlorohydrin in an organic solvent, reacting for 10-60 min at 60-90 ℃, standing to obtain milky gel, and drying, crushing and sieving under vacuum to obtain the water-absorbent resin.

Preferably, the concentration of acrylic acid in the reaction liquid is 30-40%, and can be 30%, 35% and 40%; it is more preferably 30 to 35%.

Preferably, the concentration of the sodium hydroxide solution is 20 to 35%, and specifically may be 20%, 25%, 30%, 35%.

Preferably, the neutralization degree of acrylic acid is 70 to 80%, and specifically may be 70%, 75% or 80%.

Preferably, the concentration of maleic anhydride grafted polyvinyl alcohol in the reaction solution is 3-10%, and can be 3%, 5% and 10%; it is more preferably 5 to 10%.

The preparation method of the maleic anhydride grafted polyvinyl alcohol comprises the following steps:

under the protection of inert gas, adding polyvinyl alcohol and maleic anhydride with the mass ratio of 100:15-40 into a dried organic solvent, reacting at 60-100 ℃, cooling, adding acetone for precipitation, filtering, collecting the precipitate, washing with acetone, and drying to obtain maleic anhydride grafted polyvinyl alcohol.

Preferably, the polymerization degree of the polyvinyl alcohol is 300 to 2000, preferably 500 to 1000; the alcoholysis degree is 87-89%.

Preferably, the mass ratio of the polyvinyl alcohol to the maleic anhydride is 100:20-30; the organic solvent is selected from at least one of dimethyl sulfoxide and dimethylformamide; the reaction temperature is 70-90 ℃.

Preferably, the initiator may be an initiator commonly used in the art as well as an initiator system. It may be at least one of peroxide initiator, redox initiator, azo initiator. For example, the peroxide initiator includes hydrogen peroxide, ammonium persulfate, potassium persulfate; the oxidation initiator in the redox initiator comprises hydrogen peroxide, potassium persulfate and ammonium persulfate, the reduction initiator comprises sodium bisulfate, ferrous sulfate, ferrous chloride and ethylenediamine, the redox initiator can be ammonium persulfate-sodium bisulfate, potassium persulfate-sodium bisulfate, hydrogen peroxide-ferrous sulfate, hydrogen peroxide-ferrous chloride and potassium persulfate-ethylenediamine, and the dosage ratio of the oxidation initiator to the reduction initiator in the redox initiator is 1-5: 3 to 1, preferably 1 to 3:2 to 1, more preferably 1:1. the concentration of the initiator in the reaction liquid is 0.30-0.6%, specifically 0.30%, 0.35%, 0.40%, 0.45%, 0.50%, 0.55% and 0.60%; more preferably 0.35 to 0.5%.

Preferably, the stabilizer comprises at least one of ethylenediamine tetraacetic acid, disodium ethylenediamine tetraacetic acid, tetrasodium ethylenediamine tetraacetic acid, lactic acid and sodium lactate. The addition of the stabilizer is helpful for eliminating the influence of impurities, improving the polymerization stability, stabilizing the performance of the water-absorbent resin, reducing the quality fluctuation and improving the liquid absorption and anti-rewet properties of the water-absorbent resin. The concentration of the stabilizer in the reaction solution is 0.05 to 0.5%, preferably 0.1 to 0.2%.

Preferably, the concentration of pentaerythritol diacrylate in the reaction liquid is 0.02 to 0.1%, specifically 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%; more preferably 0.03 to 0.08%.

Preferably, the concentration of epichlorohydrin in the reaction liquid is 0.03-0.2%, specifically 0.03%, 0.05%, 0.08%, 0.10%, 0.15%, 0.20%; more preferably 0.05 to 0.15%.

Preferably, the ratio of pentaerythritol diacrylate to epichlorohydrin is 1:1.2 to 3, preferably 1:1.5 to 2.5, more preferably 1:1.6 to 2.0.

Preferably, the organic solvent used for dissolving pentaerythritol diacrylate and epichlorohydrin is selected from at least one of methanol and ethanol. The introduction of methanol and ethanol uses molecules in a contracted state, so that the mutual entanglement and physical crosslinking among polymer molecules are reduced, and the crosslinking in the water-absorbent resin is mainly generated by a crosslinking agent, so that the water-absorbent resin has a proper crosslinking network structure; the resin has higher volatility during drying, is easy to form a porous structure in gel resin, increases the liquid absorption rate and liquid absorption capacity of the resin, and reduces the rewet property of the resin. The mass ratio of water to organic solvent in the reaction liquid can be 2-5: 1, preferably 3 to 4:1, and preferably 3.5 to 4:1.

preferably, the reaction temperature is 65 to 75 ℃.

The particle diameter of the water-absorbent resin particles is preferably 25 to 80 mesh, more preferably 30 to 70 mesh, and still more preferably 40 to 50 mesh. When the particle size of the resin particles is too large, the specific surface area of the particles is small, the liquid absorbing capacity is insufficient, the particle feeling is too strong, and the friction feeling is too strong when the infant moves in daytime; when the particle size of the resin particles is too small, agglomeration phenomenon easily occurs after water absorption, so that the water absorption inside the agglomerated particles is insufficient, the liquid absorption rate and multiplying power are influenced, and the liquid passing rate is reduced.

In a further aspect the invention provides the use of the absorbent core in a hygiene article, such as a baby diaper, adult diaper, sanitary napkin, menstrual pant or the like. Preferably, the sanitary article is used during daytime hours.

Accordingly, the present invention may also provide a sanitary article comprising an absorbent core according to the present invention. In one embodiment, the hygiene product is selected from the group consisting of a baby diaper, an adult diaper, a sanitary napkin, a menstrual pant.

The present invention also provides a water absorbent resin as described herein before.

Specifically, the water absorbent resin is prepared by the following method:

The invention also provides a preparation method of the water-absorbent resin, which comprises the following steps:

Wherein the water absorbent resin and the preferred embodiments of each process condition in the preparation method are as described herein before.

In the present invention, the inert gas is selected from argon or nitrogen.

In the present invention, unless otherwise specified, the parts, proportions, concentrations, etc. are by mass.

Advantageous effects

The invention provides a flexible and thin daily absorbent core with a red buttock prevention function and an extremely rapid absorption capacity and application thereof. The solution adopted by the invention is that the absorbent core adopts the water-absorbing resin with extremely fast absorption capacity, high liquid absorption multiplying power, high liquid passing rate and low rewet quantity, and the liquid is fast permeated and absorbed in the core body after penetrating the top layer, and has better liquid passing rate and air permeability after absorbing water; in addition, the water is firmly locked by the water-absorbing resin particles after water absorption, the rewet amount is low, and a large amount of water cannot flow out of the resin particles due to compression. Therefore, the absorbent core has excellent instant absorption capability, and the condition of urine leakage caused by the excessive daytime activities of infants can not occur; has high liquid absorption rate, high liquid absorption rate and low rewet amount, can remarkably reduce the flowing time of liquid on the surface of the sanitary article such as paper diaper with the absorbent core during excretion, the diaper has strong air permeability, and can fundamentally solve the problems of urine leakage and red buttocks of the diaper. In addition, the absorbent core of the present invention may contain a larger proportion of the water absorbent resin, and at this time, the water absorbent performance of the water absorbent resin may still be ensured, so that the absorbent core may have a thinner thickness, while the water absorbent resin particles are small, and the texture of the absorbent core is also softer. The absorbent core of the present invention is therefore particularly suitable for use during daytime.

Detailed Description

The present invention is described in more detail below to facilitate an understanding of the present invention.

The experimental methods in the following examples are conventional methods unless otherwise specified. The specific techniques or conditions are not identified in the examples and are described in the literature in this field or are carried out in accordance with the product specifications.

Preparation example 1:

under the protection of nitrogen, adding polyvinyl alcohol (polymerization degree is 500 and alcoholysis degree is 88%) and maleic anhydride in a mass ratio of 100:25 into a dried dimethyl sulfoxide solvent, reacting for 5 hours at 80 ℃, cooling, adding acetone for precipitation, filtering, collecting the precipitate, washing with acetone, and drying to obtain the maleic anhydride grafted polyvinyl alcohol.

Example 1:

diluting a certain amount of acrylic acid with a proper amount of water, carrying out ice water bath to 0-5 ℃, then neutralizing to a certain neutralization degree with 30wt% of sodium hydroxide solution, then adding a certain amount of maleic anhydride grafted polyvinyl alcohol, and stirring to completely dissolve; introducing nitrogen for 0.5h, adding a certain amount of initiator (ammonium persulfate-sodium bisulphite with the mass ratio of 1:1) and stabilizer disodium ethylenediamine tetraacetate into the mixture under stirring, dissolving cross-linking agents pentaerythritol diacrylate and epichlorohydrin into ethanol, dripping into the solution, stirring uniformly, stirring at a constant temperature of 70 ℃ for 20min, standing to obtain milky gel, and drying, crushing and sieving at a temperature of 110 ℃ and a vacuum degree of minus 0.09MPa to obtain the water-absorbent resin with 30-80 meshes.

The reaction conditions for each example and comparative example are shown in table 1 below.

Table 1: reaction conditions of examples and comparative examples

Performance test:

the super absorbent resins obtained in the above examples and comparative examples were subjected to a liquid absorption performance test. Wherein, the liquid absorption rate, the pressurized liquid absorption rate (0.3 psi) and the liquid absorption rate test method are according to the national standards of the people's republic of China (high-absorbency resin for paper diapers and sanitary napkins GB/T22875-2018), and the liquid is 0.9 percent physiological saline. In addition, the liquid passing rate and the rewet amount were tested as follows.

Liquid passing rate:

weighing 0.1g of the water absorbent resin finished product, and pouring into a beaker. 100g of physiological saline was added to swell. After 1h, the swollen gel was poured entirely into a cylinder (cylinder inner diameter: 2.4 cm) having a filter screen (pore diameter: 45 μm) at one end. A100 g weight of 2.4cm in diameter was slowly pressed against the gel in the measuring apparatus and allowed to stand for 1 minute. After standing, 100ml of physiological saline was added. And (3) timing for 1 minute, and weighing the physiological saline through the gel to obtain the liquid passing rate of the water absorbent resin.

The rewet amount:

80g of 0.9% physiological saline was poured into a petri dish having a diameter of 9.5cm at 23.+ -. 2 ℃ and 2.00g of the water-absorbent resin was rapidly added and the time was started, and the petri dish was rocked to uniformly disperse the water-absorbent resin particles therein. After 0.5h, 10 precisely weighed pieces of filter paper were placed on top of the gel, and a 1200g weight was pressed into the center of the dish and again timed for 5 minutes. The weight gain of the filter paper is the rewet amount of the water absorbent resin.

The results of the performance test of the water-absorbent resin are shown in Table 2 below.

Table 2: performance of Water absorbent resin

	Absorption speed(s)	Absorption capacity (g/g)	Absorption under pressure (g/g)	Liquid passing rate (g/min)	Rewet amount (g/g)
						Example 1	31	100	64	23.2	0.43
Example 2	33	114	73	18.6	0.27
						Example 3	27	108	67	25.5	0.50
Example 4	34	128	82	17.4	0.32
						Example 5	24	118	71	24.7	0.41
Example 6	28	111	65	19.3	0.39
						Comparative example 1	68	58	32	14.0	2.45
Comparative example 2	58	67	35	16.3	2.13
						Comparative example 3	51	52	37	24.4	3.12
Comparative example 4	59	70	41	25.6	2.90

As shown in Table 2, the water-absorbent resin of the present invention has the advantages of high absorption capacity at high speed, high liquid absorption rate, high liquid passing rate and low rewet, and is a water-absorbent resin with good performance suitable for the absorbent cores of sanitary articles. The water-absorbent resin of the comparative example cannot simultaneously have the above properties, and cannot well solve the problems of leakage, red buttocks, and the like when applied to an absorbent article.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and additions may be made to those skilled in the art without departing from the method of the present invention, which modifications and additions are also to be considered as within the scope of the present invention.

Claims

1. An absorbent core comprising, in order from top to bottom: a top layer, a middle layer and a bottom layer;

2. The absorbent core of claim 1 wherein the top layer is liquid permeable; the top layer and the bottom layer are at least one of woven fabric, non-woven fabric and dust-free paper.

3. The absorbent core according to claim 1, wherein the intermediate layer comprises water absorbent resin particles and a carrier for supporting the water absorbent resin particles, the carrier comprising at least one of fluff pulp, porous nonwoven material, porous woven material, tissue layer; the content of the water absorbent resin particles in the absorbent core is more than 40%.

4. The absorbent core according to claim 1, wherein the water absorbent resin is prepared by the following method:

5. The absorbent core according to claim 4, wherein the concentration of acrylic acid in the reaction liquid is 30 to 40%; the concentration of the sodium hydroxide solution is 20-35%; the neutralization degree of the acrylic acid is 70-80 percent; the concentration of maleic anhydride grafted polyvinyl alcohol in the reaction liquid is 3-10%; the stabilizer comprises at least one of ethylenediamine tetraacetic acid, disodium ethylenediamine tetraacetate, tetrasodium ethylenediamine tetraacetate, lactic acid and sodium lactate, and the concentration of the stabilizer in the reaction solution is 0.05-0.5%.

6. The absorbent core according to claim 4, wherein the concentration of pentaerythritol diacrylate in the reaction solution is 0.02 to 0.1%; the concentration of the epichlorohydrin in the reaction liquid is 0.03-0.2%; the ratio of pentaerythritol diacrylate to epichlorohydrin is 1:1.2 to 3.

7. The absorbent core according to claim 4, wherein the organic solvent for dissolving pentaerythritol diacrylate and epichlorohydrin is selected from at least one of methanol, ethanol; the mass ratio of water to organic solvent in the reaction liquid is 2-5: 1.

8. the absorbent core according to claim 4, wherein the water absorbent resin particles have a particle diameter of 25 to 80 mesh.

9. A sanitary article comprising an absorbent core according to any one of claims 1-8.

10. A water absorbent resin according to any one of claims 1 to 8.